Electric-motor turbine-vane pumps, also called turbine, periphery, tangential, regenerative, turbulence and friction pumps, have heretofore been proposed and employed for use in automotive fuel delivery systems. Pumps of this character typically include a housing adapted to be immersed in a fuel supply tank with an inlet for drawing fuel from the surrounding tank and an outlet for feeding fuel under pressure to the engine. An electric motor includes a rotor mounted for rotation within the housing and connected to a source of electrical energy for driving the rotor about its axis of rotation. A turbine impeller is coupled to the rotor for corotation therewith, and has a periphery with circumferential arrays of pockets extending around each axial edge of the periphery. An arcuate pumping channel with an inlet and outlet at opposed ends surrounds the impeller periphery for developing fuel pressure through a vortexlike action between the pockets of the rotating impeller and the surrounding channel. One example of a fuel pump of this type is illustrated in U.S. Pat. No. 3,259,072.
A general object of the present invention is to provide an electric-motor turbine-vane fuel pump of the described character that features an impeller having improved pressure and flow characteristics, particularly under hot fuel handling conditions in which the pump might otherwise be susceptible to vapor lock. Another and related object of the present invention is to provide a fuel pump of the described character featuring an improved impeller construction that is economical to manufacture and assemble into the pump arrangement. Yet another object of the invention is to provide a pump of the described character having improved impeller vane efficiency and strength.